How to use host network for docker compose?

i think you should define the docker-compose file like this: This is just an example, please read the docuementation: https://docs.docker.com/compose/compose-file/#network-configuration-reference

version: "3"
services:
  web:
    image: conatinera:latest
    networks:
      mynetwork: {}
    deploy:
      replicas: 1
      resources:
        limits:
          cpus: "0.5"
          memory: 4G 
      restart_policy:
        condition: on-failure
    ports:
      - "18080:8080"
networks:
  mynetwork:
    external: true
    name: host

You are mixing options that are invalid on either compose and swarm deployments.

If you are deploying with docker-compose up then your compose file should be like this:

version: "3"
services:
  web:
    image: conatinera:latest
    network_mode: "host"        
    restart: on-failure

Te options deploy is ignored on compose mode and the ports option is ignored when using host mode networking. I recommend to don't use host mode networking and use a reverse proxy in another container to balance your scaled containers.

---

(Feel free to ignore this part of the answer as you clarified that you aren't using swarm deployments).

If you are using swarm deployment then your compose file should be like this:

version: "3.4"
services:
  web:
    image: conatinera:latest
    deploy:
      replicas: 1
      resources:
        limits:
          cpus: "0.5"
          memory: 4G 
      restart_policy:
        condition: on-failure
    networks:
      - host

networks:
  host:
    name: host
    external: true

Again, published ports and host mode networking do not mix. Also is probably that your scaling will fail because all the containers will try to bind to the same port. I recommend to don't use host mode networking and let docker load balance your replicas.

The equivalent configuration for docker-compose v3 is using the network_mode key: https://docs.docker.com/compose/compose-file/compose-file-v3/#network_mode

You should set network_mode to "host" in your docker-compose.yml.

If using docker swarm, see codestation's answer.

I was facing the same problem. I found that when network_mode is set to host, port mapping doesn't work as the container will look for the port of the host. So, removing the port mapping worked for me like the following.

services:
  web-abc:
    build: ./abc
    # ports:
    #   - "7000:7000"
    volumes:
      - .:/code
    network_mode: host